PI-3: Best AVI Codec/Format for Background Image?

I've read all the FAQ on AVI and know that there will be improvements for AVI export in due time.

I don't want to install the albeit free, potentially problematic Panasonic DV codec for I've had a long headache just getting my JVC SD camcorder's codecs to work :)

I also have Sony Vegas 6 at this point and rolled back my Windows Media Player to 10 for it's less bloated and more stable for me. Loading new codecs can be tricky and I want to avoid them unless absolutely necessary.

And, I may not need to anyway...

So far, I've been using uncompressed AVI xports from Vegas just to play it safe for PI, but it's impractical for two reasons:

--- Huge file = A) takes up HD space and B) must put strain on PI (as it would any app playing back a 1 or 2 Gb file).

At this point, I use these AVI to create or map effects that I then export to Vegas to composite on the AVI's original edit. Otherwise put, the AVI I use in PI is essentially a stand-in" file.

So...

--- What is the best recommended codec/format/compression (i.e. the one you guys use the most at PI headquarters) for such "stand-in" AVIs?